In monitoring optical fiber transmission projects, it is not uncommon for optical transceivers and front-end signals to mismatch. The root cause is often that the signal format is not confirmed during model selection. This article sorts out the key points for the selection of multi-channel video optical transceivers from three aspects: SD and HD, number of channels, and reverse data.

First distinguish between empty baseband and high-definition interfaces

Standard definition surveillance commonly uses multi-channel baseband video optical transceivers to transmit analog video signals from cameras or codecs. One fiber can carry multiple BNC channels, typically such as8-channel video + 1-channel reverse 485 data video optical transceiver. High-definition signals use HDMI, DVI, SDI and other interfaces. The single fiber corresponding to the optical transceiver usually carries fewer channels. If the standard is selected incorrectly, the entire set of equipment will not be used at all, and the cost of rework is very high.

Calculate fiber core and margin according to channel number

The number of passes determines the fiber amount and cost of the project. It is recommended to plan according to the following principles:

• Areas with densely located points use 8-channel baseband to converge, one fiber with multiple channels, saving optical cable resources;
• The high-definition interface is evaluated based on the number of channels and one fiber. When expansion is needed, add one set instead of forcing it;
• One or two channels are reserved for each set to facilitate the subsequent addition of cameras and avoid replacement of the entire set.

Before laying out the cable, list the number of points and transmission distance in each area into a channel table, and calculate based on the principle of the minimum number of fiber pairs, the link cost and margin will be much clearer.

The reverse data plan is determined together with the selection

Points with dome cameras need to transmit control instructions back, and only models with reverse data channels can close the loop; when there is no dome camera but there are independent signals such as alarms and access control that need to be transmitted back, it can be configured2-way bidirectional RS485 data optical terminaltransmitted separately. The selection order is recommended to be video format first, then number of channels, then data and audio. It is not easy to miss items in this order. The EB-LINK optical transceiver product line covers the above configurations. You can call 0755-83179002 to obtain a selection comparison table. Engineers will give paired suggestions based on the point table.

After completing the three-step process of format, channel number, and data, there is basically no error in the selection of the complete machine.